<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Untitled Document</title>
</head>

<body>
<form action="" method="post">
<input name="caja" id="caja" type="text" value="<?=$_POST['caja'];?>" />
<input type="submit" value="Borrar" name="borrar" />
<input type="submit" value="Editar" name="editar" />
</form>
luego desde PHP tienes:

<?
if(isset($_POST['borrar']))
	{
	echo "borra?".$_POST['caja'];
	}
if(isset($_POST['editar']))
	{
	echo "edita?".$_POST['caja'];
	}
?>
</body>
</html>
